How do I convert my linked group objects to be local objects?
Backup your scene.
Go to Object Mode.
Select all the objects in the scene (A)
Go to Object>Apply>Make Duplicates Real (Shift+Ctrl+A)
With everything still selected, press L and Make Local>Selected
Objects, Data and Materials or choose All.
Set the Outliner to Groups.
Press A to select all the groups in the Outliner.
RMB and choose Unlink Group.
Set the Outliner to Same Types
Select all in the Outliner, RMB and choose Delete to remove all the
extraneous empties.